Transcript IV. Cenozoic (65 - 0 mya)

IV. Cenozoic (65 - 0 mya)
IV. Cenozoic (65 - 0 mya)
IV. Cenozoic (65 - 0 mya)
The major groups of mammals had evolved in the Jurassic and
Cretaceous.
IV. Cenozoic (65 - 0 mya)
The major groups of mammals had evolved in the Jurassic and
Cretaceous. The extinction of the dinosaurs opened many niches, but the
mammals were hammered by extinctions, too.
IV. Cenozoic (65 - 0 mya)
The major groups of mammals had evolved in the Jurassic and
Cretaceous. The extinction of the dinosaurs opened many niches, but the
mammals were hammered by extinctions, too. Small mammals, however,
quickly radiate into most ecological niches except large predators.
IV. Cenozoic (65 - 0 mya)
In the absence of dinosaurs, the birds radiated:
Diatryma (Gastornis) in
NA/Asia
seed eater?
IV. Cenozoic (65 - 0 mya)
In the absence of dinosaurs, the birds radiated:
Phorusrhacids in SA: Top Predators
IV. Cenozoic (65 - 0 mya)
In the absence of dinosaurs, the birds radiated:
Phorusrhacids in SA: Top Predators
Largest one yet, found in
Argentina in Oct. 2006,
probably stood over 10 feet tall.
Chiappe and Bertelli. 2006.
Nature 443:929.
2.3 ft
condor
IV. Cenozoic (65 - 0 mya)
MAMMALIAN RADIATIONS:
IV. Cenozoic (65 - 0 mya)
The nature of these radiations varied on the different,
separated continents
IV. Cenozoic (65 - 0 mya)
The earliest marsupials evolved in North America, but the were
practically wiped out there at the K-T. They didn't recover in NA, but
weathered the K-T (and ultimately dominated the fauna) in the southern
supercontinent of SA, Antarctica, and Australia, eventually radiating into all
ecological niches.
late Cretaceous Alphodon,
a Didelphiformian (common
marsupial group)
IV. Cenozoic (65 - 0 mya)
The earliest Cenozoic marsupials are in SA (Paleocene), but by the
Eocene they are present in Antarctica and Australia. They begin as
insectivores...
Argyrolagus (SA)
IV. Cenozoic (65 - 0 mya)
then radiate as large herbivores (in Australia, primarily)...
Diprotodon
IV. Cenozoic (65 - 0 mya)
and finally radiate as top predators.
'cat-like'
Thylacoleo
Marsupial "Lion"
(Australia)
IV. Cenozoic (65 - 0 mya)
and finally radiate as top predators.
'cat-like'
Thylacosmilus (SA and Australia)
IV. Cenozoic (65 - 0 mya)
Borhyaena (SA)
and finally radiate as top predators.
'Dog-like'
Thylacine (Australia)
IV. Cenozoic (65 - 0 mya)
In the isolation of Australia, they radiated to fill all mammalian
niches:
Insectivore
“teddy bear”
niche
45 species of terrestrial
herbivores (Wallabies and
Kangaroos
Nectarivore
Fossorial
Honey Possum
IV. Cenozoic (65 - 0 mya)
In the isolation of Australia, they radiated to fill all mammalian
niches:
Arboreal Glider
Arboreal Herbivore/Frugivore
brush-tailed Possum
IV. Cenozoic (65 - 0 mya)
In the isolation of Australia, they radiated to fill all mammalian
niches:
'cat-like'
Predator
Quolls (several species)
IV. Cenozoic (65 - 0 mya)
In the isolation of Australia, they radiated to fill all mammalian
niches:
'dog-like'
Predator
IV. Cenozoic (65 - 0 mya)
In the isolation of Australia, they radiated to fill all mammalian
niches:
Omnivore/Scavenger
Tasmanian Devil
IV. Cenozoic (65 - 0 mya)
In SA, in addition to the marsupials, there were placental mammals - but
only radiating as large herbivores:
Toxodon
IV. Cenozoic (65 - 0 mya)
and a notable mammalian clade, the Xenarthans - Sloths, Armadillos,
Anteaters - were diverse and abundant in SA faunas:
Glyptodon
Megatherium
IV. Cenozoic (65 - 0 mya)
and an Africarabian fauna evolved in isolation on Africa/Arabia - the modern
group called that Afrotheria:
Aardvarks
Tenrecs
Hyraxes
Elephants
Elephant Shrews
Golden Moles
IV. Cenozoic (65 - 0 mya)
- Paleocene (65-55 mya)
The multituberculates dominated the
"rodent niche" in northern continents.
Ptilodus
IV. Cenozoic (65 - 0 mya)
- Paleocene (65-55 mya)
The first large herbivores were
Pantodonts... including Titanoides and
Coryphodon. There are few direct
adaptations to an herbivorous lifestyle
Ptilodus
IV. Cenozoic (65 - 0 mya)
- Paleocene (65-55 mya)
The next clade of mammals were the Condylarths –
omnivorous ancestral to the modern ungulates
(Artiodactyls and Perissiodactlys).
Phenocodus
IV. Cenozoic (65 - 0 mya)
- Eocene (54-38 mya)
Many modern groups evolve in the northern continents:
Artiodactyls and Perrissiodactyls replace condylarths
proto- horses (Hyracotherium), tapirs, rhinoceroses, and camels,
and bats, primates (Purgatorius), and whales (Basilosaurus) evolve.
Basilosaurus
Pakicetus
Ambulocetus
Mesonychid (a condylarth)
IV. Cenozoic (65 - 0 mya)
- Eocene (54-38 mya)
Icaronycterus index
IV. Cenozoic (65 - 0 mya)
- Eocene (54-38 mya)
First Primates - Plesiadapids
(Paleocene)
Purgatorius
IV. Cenozoic (65 - 0 mya)
- Eocene (54-38 mya)
Many modern groups evolve in the northern continents:
creodonts replaced large birds as
major predators
IV. Cenozoic (65 - 0 mya)
- Oligocene (38-24 mya)
a cooling period, creating savannahs - grazers and browsers radiate
grasses evolve
Mesohippus
Calicotherium
IV. Cenozoic (65 - 0 mya)
- Oligocene (38-24 mya)
a cooling period, creating savannahs - grazers and browsers radiate
Arsinotherium
IV. Cenozoic (65 - 0 mya)
- Oligocene (38-24 mya)
IV. Cenozoic (65 - 0 mya)
- Oligocene (38-24 mya)
a cooling period, creating savannahs - browsers radiate
Indricotherium (Baluchitherium)
IV. Cenozoic (65 - 0 mya)
- Oligocene (38-24 mya)
Titanotheres
IV. Cenozoic (65 - 0 mya)
- Miocene (24 - 5 mya) – “NEOGENE”
IV. Cenozoic (65 - 0 mya)
- Miocene (24-5 mya)
Extensification of grassland habitats
Radiation of grazer fauna: camelids, horse ancestors, cervids, rhinos
IV. Cenozoic (65 - 0 mya)
- Miocene (24 - 5 mya)
True Dog and Cat Carnivores replace creodonts
IV. Cenozoic (65 - 0 mya)
- Pliocene (5 - 2 mya)
IV. Cenozoic (65 - 0 mya)
- Pliocene (5 - 2 mya)
Great American Interfaunal Exchange
Sloths, Armadillos,
Porcupines, Opposum
Deer, horses, monkeys,
cats and dogs, rodents
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
American Mastodon Mammut americanum
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
Complete Mitochondrial Genome and
Phylogeny of Pleistocene Mammoth
Mammuthus primigenius
Evgeny I. Rogaev, et al. 2006. PLoS.
Hyrax
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K) - Periodic Ice Ages
391.06
(2010)
379.1
(2005)
Last
Maximum ~
18,000 ybp
IV. Cenozoic (65 - 0 mya)
- Pleistocene (2 mya - 10K)
Extinction of the Pleistocene Megafuana
- Human overhunting and keystone effects
- Climate change
- diseases brought by humans and their dogs.